VEP, EEG and MEG studies of texture segregation processes: complete maturational course throughout adulthood

我们的大脑整合视觉世界中的所有信息以形成统一连贯的感知的方式依赖于不同的机制。其中之一是纹理的分离，这可以通过各种视觉维度来确定，例如亮度、方向、物体大小、颜色、运动等。初级视觉通路功能在早期发育和成人中得到了广泛的研究。然而，更多的综合视觉过程受到的关注要少得多。因此，发育曲线和织构偏析成熟的时间点还有待确定。此外，在这种复杂的视觉过程中，不同皮质区域之间发生的相互作用和同步才刚刚开始受到关注。近年来，用于测量大脑活动的电生理学和脑磁图（MEG）等技术已经变得足够精确，可以在所有年龄组中研究这种机制。目前的研究计划旨在描述，用这些工具：1)如何正常的纹理分离过程在婴儿期和儿童期发展；2)达到成人功能时；3)具体涉及的皮质相互作用和整合机制是什么？将在儿童（1个月-16岁）和不同年龄的成人（20-60岁）中获得低水平和纹理分离的视觉诱发电位以及脑电图伽马活动和脑磁图记录。为了在电生理学和脑磁图研究中获得复杂视觉过程的行为相关性，还将获得整合和分割的视觉知觉测量。建议的方法是独创的，因为它将最先进的功能脑成像技术与传统的行为（神经心理学）测量相结合，研究了整个成年期纹理分离机制的完整发展过程。因为纹理分离在高级视觉处理中非常重要，这样的研究项目将更好地理解这些机制是如何发展的，以及大脑活动的类型和定位以及所涉及的相互作用。

The way in which our brain integrates all the information present in our visual world in order to form unified and coherent percepts relies on different mechanisms. One of these is the segregation of textures, which can be determined by various visual dimensions such as luminance, orientation, size of objects, color, motion, etc. Primary visual pathway function has been extensively studied during early development as well as in adults. However, more integrative visual processes have received much less attention. Thus, the developmental curve as well as the point at which texture segregation becomes mature has yet to be determined. Furthermore, the interactions and synchronization taking place between different cortical areas during such complex visual processes have just begun to receive attention. In recent years, techniques such as electrophysiology and magnetoencephalography (MEG), used to measure brain activity, have become precise enough to study such mechanisms in all age groups. The present research program aims at describing, with these tools: 1) how normal texture segregation processes develop during infancy and childhood; 2) when they reach adult-like function; 3) what are the exact cortical interactions and integration mechanisms involved. Low-level and texture-segregation visual evoked potentials as well as EEG gamma activity and MEG recordings will be obtained in children (1 month-16 years) as well as in adult groups of different ages (20-60 yrs). Visuo-perceptual measures of integration and segmentation will also be obtained in order to have behavioral correlates of the complex visual processes at study with electrophysiology and MEG. The suggested approach is original in that it combines state-of-the-art functional brain imaging techniques with traditional behavioral (neuropsychological) measures in the context of a study of the complete developmental course throughout adulthood of texture segregation mechanisms. Because texture segregation is so important in higher visual processing, such a research program will provide a better understanding of how these mechanisms develop, as well as of the type and localization of brain activity and interactions involved.